Distribution of intelligence



I "1,633,082 F 9 1.; ESPENSCHIED msmxstiflou OF INTELLQIGENICE Filed Jan. 25., 1922 4 Sheets-Sheet 1 IINVENTOR L E qu'cM 4 6 ATTORNEY 1,6 2 June 21,1927. I ESPENSCHED 33,08-

DI STRIB UTION 0F INTELIJIGENCE 4 Sheets-Sheet 2 Filed Jan. 25. 1922 INVENTOR ATTORNEY Z LIWM June 21, 1927. 82

L ESPE NSCHIED DISTRIBUTION OF INTELLIGENCE Filed Jan. 25. 1922' 4 Sheets-Sheet INVENTOR LES/BMW ATTORNEY Patented June 21, 1927.

1,633,082 PATENT OFFICE;

UNITED STATES LLOYD ESPENSCHIED, OF QUEEN S, NEW YORK, .ASSIGN OR TO'AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A. CORPORATION OF NEW YORK.

DISTRIBUTION or INTELLIGENCE.

Application filed January 25, 1922. Serial No. 531,803.

This invention relates to signaling systems, and more particularly to systems for distribution of news, amusement and the 1 e.

5 The field of communication may be considered to be broadly divided into 'two classes, first, those communications destined between particular or individual points which are desired tol e kept more or less confidential, and second, communications involving a general dissemination of intelligence among a large number of individuals or points and which are not confidential.

eretofore the telephone art has been developcd along lines of communication falling into the first class above mentioned. It is the purpose of the present invention, however, to provide a system whereby the telephone art may be applied to communications ofthe second class.

In carrying out the invention, it is proposed to organize ,a system in which intelligence, such as music and news, may be transmitted from points at which the intelligence originates to a common distributing point.

he signaling currents will then be amplified and distributed over different lines leading to local exchanges or distributing points, at which points the 'communlcations Wlll be simultaneously impremed upon the various circuits extending to subscribers. In order that the energy transmitted over the subscribers circuits may be sufiicient to operatea loud speaker at the subscribers station, for

example, the signaling. currents may be amplified at the pointsof distribution.

In order to obtain high quality and freedom from noise interference, it is preferred to transmit the signals representing the news (1211'1'181 currents, although the inventionis not limited to the use of carrier currents for transmission. purposes. By employin carrier currents, however, having a-sufiic1ently high'frequency with respect to the width of the b duce the low frequency signaling currents, the distortion. resulting from ordinary tele phonic transmissions will. be practically eliminated. Another advantage inherent in the we of carrier currents resides in thefact thatbymultiplexingthe circuits, difi'erent carrier frequencies maybe assi ed to the transmission of a number of di e'rent'forms of amusement and news which are transmit- *0 or other form of. amusement by means of and necessary to accurately reproted simultaneously over the system, so that the subscribers will be enabled to choose the particular form of amusement or news desired. The feature already referred to of arranging for amplifying at points at which. the circuits are branched, is of considerable importance, as this renders it possible to maintain the volume of energy Sufliciently high for efficient transmission without pro-' viding individualamplifiers foralarge number of circuits.

The invention also comprehends the superposition of a distributing system such as above described uponthe ordinary telephone plant, particularly the local plant, and the combination with an ordinary subscribers subset of a carrier current lou speakin receiving set, whereby the news or other orm of amusement may be received without interfering withthe use of the subscribers circuit for ordinary telephonic communication. The distributing system may also be" superposed in accordance with the present invention upon a power distributing net work such as that of; a. large city, in which case, at each subscribers premises a loud speaking receiving set may be associated with the power circuit by suitable switching means. In certain instances it may be found expedient to provide special circuits for the distribution of amusementand information, rather than to superpose the distributing system upon existing circuits already employed for other purposes, and in other instances, combinations ofthe severalmethods may be used. The invention will now be more fully understood by reference to the followin description, when read iii connection wit the accompanying drawings, of whlch Flgure 1 95 shows a schematic layout of a system forthe distribution of amusement or intelligence in accordance with the present invention; Fig. 2 is av schematic diagram of the circuits to be employed at the main distributing station; 1

ig. 3 shows arrangements for impressing the distribution currents upon a plurality of subscribers circuits simultaneously; Figs. 4, 5, 6 and 7 are diagrams of circuit arrangements at theindividual subscribers stations; 5 Fig. 8shows how a power circuit may be --empl0yed for the transmission of amusement .or information where the power circuit 1s an alternating current circuit, and Fig. 9 shows in simplified forms how a power system propose, lines L L L the inaindistributing station M to the sta:'

viding subscribers with directcurrent power may be employed for transmitting intelligence.

Referring to Fig. 1, the entire collecting and distributing system is indicated schematically. In this figure points 1, 2 and 3 represent sources of the original amusement, music or news to be transmitted. For example, point 1 may be a classical concert point 2 may be a source of popular music ant point 3 may be a station at which a person is reciting the latest news or a phonograph is sending out. rceurrently a standard news bulletin. The sound at each of these points may be transmitted telephonica'lly either at carrier or ordinary frequencies to a main distributing station M, from which the several communications are distributed by a network through central ofiices A, B, C, D and E to the subscribers lines proper. For this purand L extend from tions A, B, C and E, respectively. At each of these four stations local lines radiate out in various directions to subscribers. At station C, a line L, also extends to the station D, so that transmission to the latter station takes place through an intermediate station. Local lines also radiate out from the station D and, if desired, local lines may be branched at points intermediate between local distributing stations, as indicated at 10 and 11, connection with lines L, and L respectively. It is also within the invention to transmit the information over local circuits radiating from the main distributing station to local subscribers in the neighborhood thereof, as is indicated at 12.

One of the features of the system resides in the association with it of suitable amplifiers such, for example, as vacuum tube amplifiers. These are located in the system just ahead of the points from which diverging lines radiate. For example, the currents transmitted from the original sources 1, 2 and 3 over the lines L,, L, and L extending to the main distributing station, may be amplified by amplifiers A,, A and A located in said lines at the main distributing station. Likewise, amplifiers A A A A andJA are arranged at these stations in the main lines connecting the stations with the main distributing station M. By thus amplifying in the different central offices, for example, the transmission 'as it enters the ofiices, the currents over the trunk lines may be kept normal and there will be available suflicient energy for supplying all of the inbscribers circuits radiating from the ofices.

The arrangement of the collecting system and thecircuits at the main distributing station is shown in greater detail in Fig. 2. Transmission from the original sound sources 1, 2 and 3 may occur at either ordinary teleerates to vary phone frequencies or at carrier frequencies. Collecting station 3, for example, transmits from the transmitter T over the line L to the main distributing station at ordinary telephone frequencies, the band being extended in width to say about 5,000 or 10,000 cycles toobta'in the high quality necessary for music transmission, instead of limiting the band to 2,000 or 3,000 cycles as is the case in ordinary telephonic transmission. This may be readily accomplished by proper design of the transmitter and transmission circuits in accordance with principles well known in the art. At the main distributing station M, the wide band thus transmitted is modulated by a carrier frequency from a source S, supplied at the main station. For modulating purposes, of modulator M may be employed, as, for example, a vacuum tube modulator of the type disclosed in Carson Patent, No. 1,343,307, of June 15, 1920.

Collecting station 2 is provided with a transmitter T and the modulator M which is supplied locally with the carrier frequency from the source S,. The modulator M may be similar to the modulator M and if it is desired to transmit only one side band, a band filter BF, of the Campbell type may be provided at the point 2 for suppressing one of the side bands and transmitting the other. By means of this apparatus, transmission from the point 1 to the main distributing station occurs at carrier frequencies.

The apparatus associated with the line L, illustrates ,how carrier transmission may be employed from an outlying point to the main distributing station with the carrier source located at the main station. As shown, the source S, is connected to the line L, through a filtering apparatus F,, if desired, and a Campbell filter F, is connected between the point at which the source S, is associated with the line and the amplifier A,. The filter F, may be arranged to transmit one side band and suppress the carrier frequency, and the other side band, if desired. At the station 1, the transmitter T,, which may be of any known type, op-

the amplitude of the carrier frequency transmitted from the source S, vVGI' the line L,, thereby modulating the carrier frequency in a manner analogous to any well-known type the ordinary telephone practice of supplying 1 battery or direct current carrier from the central office. In otherwords, the transmitter, instead .ofmodulating a direct current, modulates a carrier frequency from the source the functions of both a. transmitter and a modulator.

The three channel carriers thus brought into the main distributing station, are each amplified bynmeans of the amplifiers A,, A and A and are selectively superposed upon S, and thereby combines within itself a common outgoing bus 13 by means of band 10 posed upon the existing lines L L ,.L and a by means of high frequency composite sets consisting of a combination othigh-- pass and low-pass filters. Thus in the case of the line I c, for 'exan'iple, the line terminates in a jack J..-and,has a branch ex.-'. tending through a high-pass filter F to the bus connections 13. A low-pass filter F is connected tween the, jack J and the pointof connection between the line L and the bus 13. The high-pass-filter F permits the carrier frequencies to be transmitted to the line -L but prevents ordinary telephone frequencies which may be transmitted over 'the line from passing into the bus circuit.

- nections may be tending tance circuits.

existing power' circuits, the economics ofeach particulars tuation.

The low-pass filter F on the-other hand, pern'iitsordinary telephone frequencies to be transmitted to the jack through which" concircuits, the filter at the same time preventing the carrier frequencies from being transmitted to the jack. 4

The feature of einployin high frequency composite' sets of the type escribed is mainly important for transmission over long dis- For inter-office trunks or local circuits extending from the main distribut ng oiiice to subscribers, it may be cheaper-to assign or provide a special cincuit for the transmission of news and intelligence by means of carrier. frequencies than to provide high frequency composite sets such as described. Accordingly, composite sets are shown associated with the lines exto distant ofiices, while the line 12, extending to a local subscriber, is shown as being connected directly to the bus-bar 13 without the provision'of any jack and composite set enabling the use of the line for low frequency transmission. 1

At the various local distributing'stations such as A, B, C, D and E of Fig. 1, the carrier transmission is super osed en bloc upon all or asmany of thesu scribers lines as it is desired to include in the distributing provided amusement service lines -'having.

upon each a plurality of slibscribergor over will'de'pe'nd upon Fig. 3-.illustrates a number o'fpossible arrangemen-s' for superposing an amusement transmissid -upon=a plurality of subsoribers circuits atthe local distributing-stations, such as, for'example',*the station B of Fig.

former T made to other telephone...

1. The trunk line L5 is connected first with an amplifier A as illustrated, and the output circuit of the amplifier is connected in any one of the several ways indicated to the subscribers circuits branching from the distributing otlice. The problem in this case is to super-impose the high frequency currents upon the subscribers circuits with a minimum of effect upon the latter and with a minimum of selecting apparatus.

The method of superposition illustrated at lVco'nsists in providing in each of the telephone circuits included in a cable C apair of windings of a multi-winding transhaving a small mutual inductance and having a primary winding included in a branch L leading from the output side of the amplifier A The drop sides of the windings, that is, thesides adjacent to the ack through which the telephonecircuits may be interconnected for ordinary telephone conversation, are closed for high he quency currents by small condensers bridged purposes, the high frequency currents carrying music or the like will not be transmitted to the other circuit.

A modified scheme is shown at X, in which transformer windings are formed by grouping' thewires forming one side of each telephone line in one piece of cable C, and the wires forming the other sides of the telephone lines in another piece of cable C,., the two pieces then being wound up in coil form,

as illustrated, and inductively associated with a primary winding in a branch circuit L leading from the output side of the-amplifier A Condensers are shunted across the jacks of the lines as at W to prevent interference between lines connected to the lines in the cable at X and quency circuits.

In the modification shown at Y, the cable C includes a plurality of lines terminating in jacks as before, but in this case individual connections are provided between the bus leading from the output side of the amplifier A and each of the lines, these connections being conductive rather than inductive. Condensers may be included in each of these connections having capacity so proportioned .as to readily pass the carrier the high fre- -i'-requencies but offer a large impedance to ordinary telephone frequencies, and induct-ances or choke coils may be included in the I telephone lines between the jacks and the connections to the bus-bar to prevent the transmission of the carrier frequencies to lines associated with the jacks. ml...

At Z the connection is made by bridging a conductor. across, the wires of each linev and including these bridged conductors in a common piece of cable C whlch is wound in coil form similar to that shown at X and is associated with a primary winding included in a branch L, leading from the buswill, of course, be necessary to utilize someduction coil and ringer.

quencies. This tainthe communlcation carried by the frewhat more complicated and effective filtering means. Filters adapted for this purpose are well known in the art and hence, are not illustrated. In some cases the use of a more expensive type of filter may not be justified as compared with the provision of special circuits for the new type of service. As an example of how a special circuit might be provided to one or more subscribers, a branch Ii, is shown, leading from the bus-bar to the cable 0, without any provision for connection to other telephone circuits. Obviously, in the transmission of intelligence of the. kind now under consideration, privacy is neither necessary nor desirable, and as many subscribers may be included on such a circuit as transmission conditions will warrant.

Fig. 4 illustrates circuit arrangements which may be used at the subscribers end of the system. As indicated, the subscribers line terminates in the usual substation apparatus including transmitter, receiver, in-

The circuit for the loud speaker is bridged across the line, as indicated at 20, and is tuned by means of the condenser 21 and the inductance of a transformer 22. Where high carrier frequencies are employed, this selective circuit may be of the simple loosely coupled type, itbeing loosely coupled through the transformer 22 to a second tuned circuit, including the condenser 23. I In order to enable the subscriber to select any particular type of amusement or news which may be transmitted over the circuit, a switch 24 is provided which may be set in a plurality of different positions, thereby changing the inductance of the windings of the transformer 22, so that the tuned circuits. will be adjusted to any one of several carrier freenables the subscriber to obquency selected to the exclusion of other forms of intelligence which may be superposed upomthe circuit at the same time.

A simple ,form of detector, such as the associated thermal or crystal rectifier detector 25, is connected across the terminals of the tuning condenser 23, and this detector is bridged by a circuit including the loud speaker 26, which may be of any ty 0 well known in the art. The form of (etector used may vary somewhat, depending upon conditions, and where the expense is not prohibitive, more efficient types of detectors, such as vacuum tubes, may be employed if desired. The showing of the detector 25 in the drawing is therefore intended to be merely conventional, it being understood that any type of detector may be employed. In order to prevent the high frequency currents from being transmitted to the regular subscribers set, it is desirable to use some form of excluding circuit for the carrier frequencies in the telephone branch. Such a circuit is illustrated in Fig. 4, as an anti-resonant circuit 27. A simple condenser may also be connected 'in shunt with the winding of the ringer for the purpose of by-passing carrier currents. It will be understood, of course, that a low-pass filter is a more complete solution for the problem, although a more eX- pensive one.

Fig. 5 is similar to Fig. t except. that it shows a connection whereby the polarizing electromotive force for the rectifying detector is derived from the battery supply of the telephone circuit. As shown, there is a direct. current path from one side of the line through the retard coil 29, through the potentiometer 30 to the upper terminal of the detector, and thence over a special connection between the upper terminals of the two windings of the transformer 22 to the other side of the line. A tap may be taken from the potentiometer at any point to the other side of the detector as indicated. Obviously, a similar method may be utilized to supply operating current or any other type of current.

In Fig. 6, a low-pass filter 31 is included in the connection extending to the subscribers set to prevent the transmission of the carrier frequencies to the subscribers set, and band filters BF BF and BF are employed in the loud speaker circuit for selecting the desired high frequency trans mission. Anyparticular filter may be connected in the circuit by means of a suitable switch 32. ..A vacuum tube amplifying detector 33 is employed for detecting high frequency currents and the loudspeaker 26 is with the vacuum tube detector in a well-known manner.

A similar arrangement is shown in Fi 7, but in this case the expense of PIOVlt ing the low-pass filter 31 is avoided by using a 'subscribers set of the anti-side tone type, as illustrated. The anti-side tone circuit shown is well known in the'art, and the elements are so proportioned that the transmitter and receiver are conjugate. The hi h i to keep 2O frequency currents, when transmitted to t is subscrlbers set, may react in the transmit-' ter, which may function as adetector to reproduce the low frequency currents corresponding to the signal impressed upon the carrier' frequencies. If an ordinary substation set were used, these detected currents would affect the receiver so that interference would occur if the set were to be used for ordinary telephonic purposes, while amusement, news and the like are superposed upon the circuit. By arranging the receiver so as to be conjugate with respect. to the transmitter, however, any high frequencies detected by the transmitter can- Consethe necessity for filtering apparatus high frequency currents out of the substation is not necessary.

Instead of using telephone circuits for not tie-transmitted to' the receiver. quently,

, the transmission of amusement and news i mally designed for the transmission the filamentservice, power circuits may be employed. For examplejin Fig. 2, a connection may be extended from the bus 13 to a power circuit, as indicated at 35, a suitable condenser being used to prevent low alternating frequencies from thepower circuit from reacting upon the telephone circuits. Similarly, the connection to the power circuit may be made at any of the local distributing stations. For example, in Fig. 3, .the connection 36 may be extended from the common bus-bar to a power circuit, condensers being included as with the telephone circuits.

The arrangement of the apparatus associated with the power circuit, so far as the subscribers station is concerned, is illustrated in Fig. 8. In this figure, a typical alternating current power circuit is shown, having the usual step-down transformer 37, cut-out box 38, and meter 39 includedbetweenthe power circuit-and the load, such as lamps or other current consuming devices 40. The receiving circuit for the high frequency amusement and news service is bridged across the power circuit, for example, between the'cut-out box 38 and the meter 39, and includes selecting devices similar to those shown in Figs. 6 and 7. A vacuum tube detector 41 is illustrated and and plate currents for supplying this tube may be derived from the power circuit through a suitable transformer 42, vacuum tube rectifiers and a filter being provided to rectify the alternating current for the space circuit of the tube 41 as illustrated.

A loud speaker 26v is associated with the detector asin the other substation arran ements illustrated. In order that the hlgh frequency currents mayv be transmitted through the transformer 37, which is norof relatively low frequency power currents, conb'efore to prevent interference 94 leads to a load 65,

densers 43 and 44 may be bridged across the terminals 'of the transformer to provide a pafll for high frequency currents. In some instances the provision of this condenser will not be necessary, as the capacity of the 70 transformer itself may be suflicient to'permit the passage of the high frequency currents. The inductance of the meter 39 may be utilized to choke the carrier frequencies from the load circuit.

Fig. 9 shows an arrangement whereby the news and amusement service may be superposed upon a power circuit over a part of which alternating power currents are transmitted, and over the remainder of which direct power currents are transmitted. In this figure, designates an alternating current power generator associated through a transformer 51 with a power line 52. A circuit 53 is bridged across the power circuit and leads to a modulator 54 through a high-' pass filter 55. The modulator is supplied with a suitable source of carrier frequency 56, whereby the amusement or news currents are translated into carrier currents and passed through the filter 55 to the power line. A low-pass filter 57 serves to.prevent the high frequency currents from passing into the generator circuit. At a power substation along the line, the alternating currents are passed through a transformer 58 to a motor generator set 59, whereby the alternating currents are translated into direct currents and passed through the low-pass filter 60 into the local power circuit 61. 100 The high frequency currents are shunted around the substation apparatus by means of a circuit 62, including the high-pass filter 63 and a lowpass filter 64 is inserted between the transformer 58 and the junction 105 point of the circuit 62 with the line 52 to preventthe high frequency currents from passing into the transformer 58 and the other substation apparatus.

Subscribers circuits may be supplied with power and amusement service in several ways. For example, a subscribers circuit which may be incandescent lamps, for example, through a low pass filter 66. A high frequency branch 67 including the high-pass filter 68 leads to a detector 69 of any well-known type in the output circuit of which is arranged a loud speaker 70', and, if desired, a plurality of telephone receivers 71, whereby various individuals may listen to the amusement ornews service. a

A subscribers circuit 72, on the other hand, is shown as including a plurality of arc lights 73, which may not only function as lamps, but in accordance with the wellknown principles of the speaking are, may

also function as combined-detectors and loud speakers to transmit the amusement or intelligence in the form of vocal sounds. The

asis well known, 1s a fine drawn wire which by its thermal action detects the high frequencv currents and transmits them as low vocalsounds to the ear oi the listener.

The principles here illustrated readily adapt themselves to the distant controlv of some remote current consuming device, such as a motor. For example, a branch circuit 80 leads to a D. Crmotor 81 through a lowpass filter 82, the latter serving to keep the high frequency currentsfrom the motor circuit. A high frequency branch 83 including a high-pass filter 84 leads to a detector 85 in the output circuit of which is a controlling relay 86. The controlling relay in turn controls the opening or closing of the circuit of the motor 81. In order that this apparatus may be operated from a distant point, there is shown at the generating end of the circuit a branch 90 including a band filter 91 and leading through a controlling key 92 to a high frequency source 93. When the key 92 is closed, high frequency currents are superposed upon a power circuit and operate the detector 85, which in turn, through the relay control, closes the circuit of the remote motor 81 so that it will operate under the powercurrents supplied from the power generating station.

With regard to the utilization of power circuits for the transmission of news service, it should be noted that such circuits readily adapt themselves to the broadcast transmission of intelligence because the necessity for privacy is not present and the service requires merely one-way circuits. Furthermore, the transmission efficiency of such circuits will be relatively good for the high frequency broadcasting service by reason of the considerable copper involved in the power network. The amplification required at the terminal will thus be relatively small in any case, and in view-of the large power carrying capacity of such a system, it will generally be possible to amplify the cur-' rents to a very high degree at the transmitting end before superposing them upon the power system.

It will be obvious that the general principles herein disclosed may be embodied in many other organizations widely different from those illustrated without departing from the spirit of the invention asdefined in the following claims.

What is claimed is:

1. In a system for distributing amusement, news and the like, a central station, a pluralit of subscribers stations, subscribers lines extending from said central station to said subscribers stations, a common terminal at the central station to which said lines are connected in multiple, means to translate intelligence into high frequency carrier currents, means to apply said carrier currents to said common terminal for simultaneous transmission over a plurality of said lines to a plurality of said sub-' scribers stations, and detectors at said substations for simultaneously detecting the same intelligence from said carrier currents at a plurality of said substations.

2. The method of distributing amusement, news and the like, which consists in producing several different types of intelligence, translating each type of intelligence into a carrier current having a different frequency characteristic of the intelligence translated, superposing the several carrier currents upon a common terminal at a central station, simultaneously transmitting the several carrier currents along individual guiding paths to a plurality of subscribers stations, selecting at each subscribers station the carrier current transmitting the type of intelligence desired to the exclusion of other carrier currents, and at certain subscribers stations simultaneously detecting from the selected carrier current one type of intelligence, and at other subscribers stations simultaneously detecting from another selected carrier current another type of intelligence.

3. In a system for distributing amusement, news and the like, a central station, a plurality of subscribers stations, sub scribers lines extending from said central station to said subscribers stations, a common terminal at the central station to which said lines are connected in multiple, a plurality of sources of intelligence, means to translate intelligence from each source into a carrier current of different frequency, means to simultaneously super-pose the several carrier currents upon said common terminal for simultaneous transmission of the several carrier currents over each ofa plurality of lines, means at each subscribers station for selecting the carrier current transmitting the desired intelligence to the exclusion of other carrier currents, and detectors ateach substation, the detectors at certain substations simultaneously detecting from the selected carrier current the same desired.

intelligence, and the detectors at other-substations simultaneouslydetecting from another selected carrier a different desired intelligence.

4. In a system for distributing news, amusement and the like, a central station, a plurality of subscribers stations, subscribers lines extending from said central station to said subscribers stations, a common terminal at the central station to which said lines are connected in multiple, a plurality current transmitting one desired type of inmethod which consists telligence to the exclusion of other carrier currents while other stations may select a carrier current transmitting a different type of intelligence to the exclusion of other carrier currents, and detecting means at each substation for simultaneously detecting the intelligence corresponding to the particular carrier current selected at each substation.

5. The method of distributing news, amusement and the lil-:e, whi -.h consists in collecting the information which it is desired to transmit at a central point, translating the intelligence into electrical currents, impressing the electrical currents upon individual circuits radiating from said central point, amplifying the currents before impressing them upon the radiating circuits, amplifying the currents received at the terminals of certain of the radiating circuits, and-impressing the amplified energy upon branch circuits leading from said terminals.

6. In a system for distributing an'iusement, news and the like by collecting the intelligence to be transmitted at a central point and transmitting it in the form of electrical energy over circuits branching from said point to outlying points, and from said outlying points over other circuits in turn branching therefrom, the in amplifying the electrical energy at each distributingpoiut in the system from which branch lines radiate. 7. In a system for distributing amusement, news and the like means'for collecting the intelligence to be transmitted and translating it into electrical energy at a central point, means for amplifying the energy at said point, branehlines extending fro said central point to outlying points, means for amplifying the ener y at certain of said outlying points, and branches extendingfrom the output of said last mentioned amplifying means to subordinate outlying v "8. In a system for distributing news,

amusement and the like, means for collectbrane ing the intelligence" which it is desired to transmit and translatin it into electrical energ at a central I iilines extending from said central oi it to outlying points, subordinate branch' es extending roni outlying points to subordinate points,

point, a plurality of and means for amplifying the electrical energy at each point in the system from which branch lines radiate.

In a system for transmitting amusement, news and the like, a central office, a subscribers station, a transmission line extending from said central oilice to said subscribers station, a subscribers subset and a special receiver at said subscribei"s station, a second subscribers station, a second line extending from said central office thereto, a

subscribers subset at said second subscribers station, means to interconnect said lines at said central station so thatordinary telephone currents may be transmitted from one subscribers station over said lines to the other subscribers station, means for translating a program into a high frequency carrier current, means to apply said carrier current to said first mentioned line at said central ollice, means to prevent-the carrier current so applied from being transmitted over said interconnecting means to the other subscribers ,line, and means at said first-mentioned subscribers station for translating said carrier current into program currents to actuate said special receiver at said first-mentioned subscribers station.

10. In a system for transmitting amusement," news and the like, a central otlice, a plurality of subscribers stations, transmission lines extending from 'said central oiiice to said subscribers stations, subscribers subsets at each subscribers station, means at said central ofiice whereby any line may be interconnected exclusively to any other line for transmission of ordinar telephone currents from one subset over 0th lines to the other subset, means for translating a program into a high frequency carrier current, a common terminal at the central oilice, multiplc connections from said terminal to certain of said lines, means to apply said carrier current to said common terminal for simultaneous transmission over the lines connected thereto, means associated with said lines to prevent the carrier current applied thereto over their multiple connections from being transmitted over an ordinary telephone connection at the central ofiice to another 7 line with which it is connected for ordinary telephone transmission, means at the substations of lines to which carrier current is applied for translatin said carrier current into a program, 2111C a special receiver at said substations for receiving the translated currents. l

11.'In a system for transmitting news, amusementand the like, a central office, a plurality of subscribers stations, transmission lines extending from said central oflice to said subscribers stations, subscribers subsets at eachsubscribers station, means at said central oflice whereby any line may be interconnected exclusively to any other line Ill for transmission of ordinary telephone currents from one subset over both lines to 'the other subset, means to translate intelligence from several sources into carrier currents having different frequencies, a common terminal at the central oiiice, multiple connec tions from said terminal to certain of said lines, means to apply said carrier currents to said common terminal for simultaneous transmission over the lines connected thereto, means associated with said lines to prevent the carrier currents applied thereto over their multiple terminals from being transmitted over an ordinary telephone connection atthe central otiice to another line withwhich any line is connected for ordinary telephone transmission, means at the substations of lines to which carrier currents are applied to select the carrier current transmitting desired intelligence, means at said substations to detect from the selected carrier the intelligence transmitted thereby, and special receivers at said substations for receiving the detected intelligence.

12. In a system for distributing amusement, news and the like, a main central office, linesextending from said main central oflice to outlying switching stations, means at said central ofiice for switching said lines into connection with each other for the transmission ofordinary telephone currents, lines extending from said outlying otiices to subscribers stations, switching means at said outlying otiices for interconnecting subscribers lines with each other or with the lines extending to the main central oflice for the, transmission of ordinary telephone currents over said subscribers lines, a plurality of sources ofintelligence of different types, means .to translate intelligence from said sources into high frequency carrier currents having frc utncies characteristic of the different types 0 intelligence, a common terminal at said main central ofiice upon which said carrier frequencies may be simultaneously impressed, connections from said terminal to said telephone lines, means asso ciated with-said connections for discriminating between low frequency and carrier frequency currents, connections from the lines leading to the main central oflice at each outlying station for simultaneously impressing said carrier frequencies upon the subscribers lines, discriminating means associated with said connections for discriminating between high frequency carrier currents and or'dinary telephone currents, a program receiver set at each subscribers station, means at the subscribers station for selecting high frequency carrier currents corresponding to the desired type of intelligence to the exclusion of other carrier frequencies and ordinary telephone currents, and means for translating the selected frequency into low frequency currents for operating the program receiver set.

13. In a system for distributing amusement, news and the like, a central ottice, .telephone circuits terminating at said central oti'ice, switching arrangements for interconnecting said telephone circuits for communication at ordinary telephone frequencies, a source of carrier currents, and means for simultaneously super-posing carrier frequencies from said'sour'ce upona plurality of said tclephone circuits.

lat. In a system for distributing amusement, news and the like, means for translating intelligence into electrical energy, a distributing station having a common terminal for impressing said energy upon said terminal, connections from said terminal to a plurality of telephone lines, circuits for the.

distribution of power, and connections from said common terminals to said power circuits, whereby said electrical ener transmission of intelligence may e simultaneously transmitted over said telephone lines and power circuits.

15. In a system for distributing news, amusement and the like, a central station, a plurality of subscribers stations, lines interconnecting said central station with said subscribers stations,-means at said central stations for interconnecting any subscribers line with another subscribers line to the exclusion of other subscribers lines for ordinary telephone transmission, a subscribers set including a transmitter and receiver at each subscribers station, means at said central station to simultaneously impress intelligence to be distributedin the form of high frequency carrier currents upon a plurality of said lines, a special receiver at certain subscribers stations, and means to operate'sa-id special receiver at such stations by said high frequency carrier currents. V

16. In a system for distributing news, amusement and the like, a central station, a plurality of subscribers stations, lines interconnecting said central station with said subscribers stations, means at said central stations for interconnecting any subscribers line with another subscribers line to the exclusion of othersubscribers lines for ordinary telephone transmission, asubscribers set including a transmitter and receiver at each subscribers station, means at said cen tral station to impress simultaneously upon a plurality of said lines several carrier currents of different frequencies each transmitting difi'erent intelligence, a special receiver at certain subscribers stations, and means at said stations to select one carrier frequency to the exclusion of the others for operating said special receiver.

17 In a system for distributing news,

for the distributing amusement and the like, a central station, a. plurality of subscribers stations, lines interconnecting said central station with said subscribers stations, means at said central station for interconnecting any subscribers line with another subscribers line to the exclusion of other subscribers lines for ordinary telephone transmission, a subscribers set including a transmitter and receiver at each subscribers station, means at said central station to impress simultaneously upon a plurality of said lines several carrier currents of differentfrequencies each transmitting dillerent intelligence, a special receiver at certain subscribers stations, means at said stations to select one carrier frequency tothe exclusion of the others for operating said special receiver, and means associated with each special receiver for detecting from the selected carrier frequency the intelligence transmitted thereby.

"18. A transmission system comprising atransmission line over which messages may be transmitted at ordinary. telephone frequencies and-other forms of intelligence may be transmitted at carrier frequencies, a subscribers set associated with said line for use in connection with ordinary telephone fre quencies,'an auxiliary set including selective apparatus and a detector independent of said subscribers set for operating at carrier frequencies, said subscribers-set including a telephone transmitter and receiver and connections therefor so arranged that said transmitter and receiver will be substantially conjugate, whereby high he quency energy passing into the subscribers set and detected by said'transmitter will not actuate said receiver. k

19. In a directed entertainment system, a point from which a plurality of transmission lines lead to subscribers stations, said lines being connected in multiple, a station distant from the distributing point at which programs originate, means to transmit the programs at voice frequencies to the distributing point, and means to simultaneously distribute rality of said lines to a plurality of sub scribers at carrier frequencies.

20. In a directed entertainment system, a distributing point from which a plurality of transmission lines extend to a plurality of" subscribers stations, said lines being connectedin multiple, a station distant from'the distributing point at which programs originate, means to transmit the programs from said station to said distributing point at voice frequencies-means at the distributing point for translating the voice frequency currents into carrier currents of higher frequencies, and means for simultaneously distributing' the carrier currents over a plurality of said lines to a plurality of subscribers stations. r

tween the subscriber of the programs over a plu-.

21. In a directed entertainment system, a distributing point from which a plurality of transmission lines lead to a plurality of subscribers stations, said lines being connected in multiple, a station distant from the distributing point at which programs originate, means to transmit the programs to the distributing point at voice frequencies, means atthe distributing point to modulate carrier currents by the voicefrequencies transmitted from the distant station, and means to sin'iultaneously transmit the same modulated current over a plurality of said lines to a plurality of subscribers stations.

22. In a signaling system, the combination with a telephone cable comprising a plurality of subscribers loops, each loop having a telephone subscribers sub-set connected thereto and arranged for exclusive point to point telephone communication beany given loop and other loop, of a prothe subscriber of any to impress a high fregram circuit, means quency alternating carrier current upon said program circuit, means to superimpose a program signal upon said carrier current, means to inductively connect said program circuit to a plurality of the loops in said cable to simultaneously transmit said carrier current over each of said plurality of subscribers loops without permitting telephone currents originating at any subscribers station for point-to-point communication to be transmitted through said inductive means to any other loop, and receiving means associated with each of said loops to detect from said carrier current said program signal simultaneously with the transmission of point to point telephone messages over the loops. 23. In a signaling system, a pluralit of telephone subscribers loops, each loop aving a telephone subscribers sub-set connectmitted simultaneously over each of said.

loops while telephone currents origlnating at any subscribers station for point to point communication will not be transmitted through said connecting means to any other loop, and receiving'means associated with each of said loops to detect from said carrier current said program signal simultaneously with the transmission of point to point telephone messages over said loop.

24. In a signaling system, a pluralit of telephone subscribers loops, each loop aving a telephone subscribers sub-set connected thereto and arranged for exclusive point to point telephone communication between the subscriber of any given loop and a subscriber of any other loop, a pro am circuit,

means to impress a plurality 0 alternating;

. will be transmitted simultaneously over each of said loops while telephone currentsoriginating at any subscribers station for pomt to pomt communication will not be trans- 15 mitted through said connecting means to any other loop, means at each subscribers station to select from the carrier currents transmitted over the loop, the particular carrier current upon which is superposed a desired program si nal and receiving means associated with eac of said loops to detect from the selected'carrier current thedesired program signal simultaneously with the transmission of point to' point telephone messages over sai loop.

In testimony whereof, I have signed my name to this specification this 24th day of January, 1922.

LLOYD Esrnusonrnn. 

